Question

I have just entered the world of coding and am learning all about loops. I just learnt about for and while loops but don’t understand why the return different results. Can someone please explain the logic in a lay person’s terms.

/* for loop code */

$counter = 0;
$start = 1;
$end = 11;

for($start;$start<$end;start++) {
$counter=$counter+1;
print $counter;
}

The result I get is 1, 2, 3, 4, 5, 6, 7 , 8, 9 , 10

/* while loop code */

$start=0;
$end=11;

while($start<end) {
$start=$start+1;
print $start;
}

The result I get is 1,2,3,4,5,6,7,8,9,10,11

Why is that the while loop returns a result of 1 through to 11 whilst the for loop returns a result of 1 through to 10

Answer 1

In for case $start starts from 1 but in while case $start starts from 0.

Working on for –

 iteration    $start      $start<$end     counter   print   start++        
    1           1            1<11           1         1        2
    2           2            2<11           2         2        3
    3           3            3<11           3         3        4
    4           4            4<11           4         4        5
    5           5            5<11           5         5        6
    6           6            6<11           6         6        7
    7           7            7<11           7         7        8
    8           8            8<11           8         8        9
    9           9            9<11           9         9        10
   10           10          10<11          10         10       11
   11           11          11<11 
                          // (false) break

Similarly work on the while loop. It’s a paper-pencil exercise.